I’m having a problem with my small drill press. I’m using a forstner bit, (2.5” and 3.0”), to cut a decorative radius in the foot of a patio glider bench. The 2.5” worked well. When attempting the 3.0”, the chuck keeps slipping off. It’s a taper fit so I replaced it and gave it a solid tap with a dead blow mallet. I also slowed down the speed of the drill press. Still pops off.

One thought is I am only drilling 1/4 of the circle. Maybe I should butt up a piece off scrap to keep the pressure on the bit even.

I can cut this radius on my band saw but a bit would be clean and easy. Any ideas?

Chuck may not be fully seated. Emory Cloth to polish the shaft a bit, next time it pops off. Mark how far it WAS on the shaft. Then try to go a bit further up. Sometimes, one can chuck an old bolt into the chuck, and drive the chuck on a bit further. Either by that hammer, or just crank the chuck down onto the table, to push the chuck on a bit more.

3” Bit? Lowest speed you have on the Drill press. ONE finger to push the bit down into the work.

If its just the chuck, on the odd chance you got something on the spindle and or in the chuck taper you can try Break or oven cleaner on both. Saw dust, body oil (from handling) grease (from packaging) whatever can mess with the friction bond.

Lower the table as far as possible to ensure a square/direct blow on a completely open jawed chuck.

Well I cleaned the spindle taper and the inside of the chuck. Rapped in in firmly with a mallet. Used scrap blocks so the pressure on the bit would be even. Still popped off. I think it’s too big a bit for my small drill press.

So I cut the radius curve on my band saw. It worked very well. The band saw is a used Delta. I haven’t used it much so every cut is a learning experience. Seems like there is always multiple ways to get a job done. Picking the best one is the key.